Tuning of Capacitance Behavior of NiO Using Anionic, Cationic, and Nonionic Surfactants by Hydrothermal Synthesis

Abstract

In this work, NiO powders with a spherical morphology were synthesized by a simple hydrothermal technique using organic surfactants as templates and urea as the hydrolysis controlling agent. The effect of cationic (cetyl trimethyl ammonium bromide), anionic (sodium dodecyl sulfate), and nonionic (Triton X-100) surfactants for tuning the surface area, pore size, pore volume, and electrochemical properties of NiO powders was investigated. The NiO powders were characterized by X-ray diffraction, scanning electron microscopy, the Brunauer−Emmett−Teller method, cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy. We observed that the charge-storage mechanism in our NiO-based electrodes is significantly Faradic in nature rather than capacitive type. The ionic nature of the surfactant used in the preparation of NiO powders shows a considerable effect on their capacitance behavior. The specific capacitance values were found to increase in the order of NiO-T (144 F g−1) < NiO-C (239 F g−1) < NiO-S (411 F g−1) at a current density of 200 mA g−1 in 2 M KOH aqueous electrolyte solution. The NiO-S sample exhibits the highest surface redox reactivity and shows the specific capacitance of 235 F g−1 over 100 cycles at a current density of 500 mA g−1 in a life cycle test.

Synthesis of porous NiO nanocrystals with controllable surface area and their application as supercapacitor electrodes

“…5(b)). The total mass losses are slightly smaller than the theoretical value of 19.4% [44][45][46], which indicates incomplete thermal decomposition of the β-Ni(OH) 2 . The values are 19.2% for the nanoslices (corresponding to 99% NiO formation), 18.1% for nanoplates (corresponding to 94.7% NiO formation) and 17.6% for nanocolumns (corresponding to 93.4% NiO formation).…”

Surfactant-assisted electrodeposition and improved electrochemical capacitance of silver-doped manganese oxide pseudocapacitor electrodes

“…Additionally, the magnitude of charge-transfer resistances at the solid-liquid interface is in the following order: Ag/ MnO 2 (SDS) ≈ Ag/MnO 2 (CTAB) < Ag/MnO 2 < MnO 2 . If charge-transfer resistance is smaller, the pseudocapacitor provides higher specific capacitance values [10]. The slope of the straight line in a low frequency range is due to the Warburg resistance.…”

“…However, their costs are prohibitive and their materials toxic [4]. Efforts to develop more practical and inexpensive pseudocapacitive materials such as MnO 2 [5][6][7][8][9] and NiO [10][11][12] are now quite active. MnO 2 is an important and wellstudied material for supercapacitors.…”

Effect of Calcination Time on Structural, Optical and Antimicrobial Properties of Nickel Oxide Nanoparticles

“…Several techniques, such as hydrothermal [10], sol-gel [11], solid-state reaction [12], electrochemistry [13], micro emulsions [14], spray pyrolysis [15,16] and precipitation [17] methods, have been developed to synthesize NiO nanoparticles.…”